An apparatus for generating physical random numbers includes a physical random number generator configured to generate physical random numbers, a test unit configured to perform a test process to check randomness of the physical random numbers, a minimum entropy estimating unit configured to estimate a minimum entropy based on statistical information generated as a byproduct of the test process, an entropy compressing unit configured to perform an entropy compression process using the physical random numbers as an input, and an entropy control unit configured to control based on the minimum entropy a number of bits of the physical random numbers input into the entropy compression process performed by the entropy compressing unit.