To provide an automatic penetration tester, capable of detecting the load torque of a penetration rod penetrating through a disk and evaluating the stratum of a ground to be tested according to the load torque.

This hammering penetration tester 1 comprises a torque sensor 30, capable of detecting the rotational load torque of a penetration rod 4 and a lifting unit 40 which imparts a predetermined load to the penetration rod 4. Thus, the sum of the penetration energy by the addition of rotation of the penetration rod 4 and the penetration energy by the load can be calculated. A diluvial, an alluvium, and a humic soil layer which are formed of clays with different moisture contents can be determined, by analyzing the sum of these energies.