| Note | As at December 31, 2020 | As at December 31, 2019 | |
| NON-CURRENT ASSETS | |||
| Property, plant and equipment | 9 | 61,741 | 59,690 |
| Investment property | 10 | 41 | 47 |
| Intangible assets and goodwill | 11 | 646 | 735 |
| Rights of use assets | 12 | 1,309 | 1,303 |
| Financial receivables | 25.1.1 | 191 | 180 |
| Derivatives and other assets measured at fair value through profit or loss | 25.1.2 | 132 | 93 |
| Shares, interests and other capital instruments | 57 | 58 | |
| Shares and interests accounted for using the equity method | 13 | 152 | 715 |
| Other non-current assets | 17.1 | 839 | 676 |
| CO2 emission allowances for captive use | 16 | 39 | 240 |
| Deferred income tax assets | 14.1 | 1,351 | 1,318 |
| 66,498 | 65,055 | ||
| CURRENT ASSETS | |||
| Inventories | 15 | 3,123 | 4,509 |
| CO2 emission allowances for captive use | 16 | 1,735 | 965 |
| Income tax receivables | 8 | 59 | |
| Derivatives and other assets measured at fair value through profit or loss | 25.1.2 | 423 | 327 |
| Trade receivables and other financial receivables | 25.1.1 | 4,812 | 4,815 |
| Other current assets | 17.2 | 799 | 605 |
| Cash and cash equivalents | 18 | 4,189 | 1,313 |
| 15,089 | 12,593 | ||
| ASSETS CLASSIFIED AS HELD FOR SALE | 7 | 2 | |
| TOTAL ASSETS | 81,594 | 77,650 | |
| EQUITY | |||
| Share capital | 20.1 | 19,165 | 19,165 |
| Reserve capital | 20.2 | 18,410 | 19,669 |
| Hedging reserve | 20.3 | (13) | (323) |
| Foreign exchange differences from translation | 20.4 | 5 | (1) |
| Retained earnings | 20.5 | 4,951 | 3,779 |
| EQUITY ATTRIBUTABLE TO SHAREHOLDERS OF THE PARENT COMPANY | 42,518 | 42,289 | |
| Equity attributable to non-controlling interests | 20.6 | 983 | 848 |
| TOTAL EQUITY | 43,501 | 43,137 | |
| NON-CURRENT LIABILITIES | |||
| Non-current provisions | 21 | 11,207 | 9,652 |
| Credits, loans, bonds and leases | 25.1.3 | 10,025 | 10,859 |
| Derivative instruments | 25.1.2 | 385 | 107 |
| Deferred income tax liabilities | 14.2 | 345 | 920 |
| Deferred income and government grants | 23.1 | 600 | 616 |
| Other financial liabilities | 25.1.4 | 448 | 475 |
| Other non-financial liabilities | 24 | 65 | 58 |
| 23,075 | 22,687 | ||
| CURRENT LIABILITIES | |||
| Current provisions | 21 | 7,311 | 4,366 |
| Credits, loans, bonds and leases | 25.1.3 | 1,384 | 1,449 |
| Derivative instruments | 25.1.2 | 63 | 372 |
| Trade payables and other financial liabilities | 25.1.4 | 3,504 | 3,636 |
| Income tax liabilities | 476 | 58 | |
| Deferred income and government grants | 23.2 | 77 | 80 |
| Other non-financial liabilities | 24 | 2,203 | 1,865 |
| 15,018 | 11,826 | ||
| TOTAL LIABILITIES | 38,093 | 34,513 | |
| TOTAL EQUITY AND LIABILITIES | 81,594 | 77,650 |