For more than 50 years, PT TIMAH Tbk has continued to develop exploration activities to find and enlarge the amount of owned resources. In generally, exploration activity include the following activities:
Tin Reserve Table (In Tons)
| Reserve | 2021 | 2020 | 2019 | 2018 | 2017 |
| Onshore | 20,220 | 16,399 | 73,340 | 103,539 | 100,616 |
| Offshore | 279,780 | 265,913 | 254,180 | 311,819 | 276,978 |
| Total | 300,000 | 282,312 | 327,520 | 415,358 | 377,594 |
Tin Resource Table (In Tons)
| Resource | 2021 | 2020 | 2019 | 2018 | 2017 |
| Onshore | 452,858 | 404,150 | 520,810 | 502,498 | 324,037 |
| Offshore | 466,240 | 419,270 | 514,970 | 541,135 | 472,306 |
| Total | 919,098 | 823,420 | 1,035,780 | 1,403,633 | 796,343 |
