A radiation measuring apparatus (20) includes a scatterer detector (10A), an absorber detector (10B) and a processing unit (12). Pixel electrodes (2) of the scatterer detector (10A) and the absorber detector (10B) are arranged such that a distance between centers of two neighbor pixel electrodes (2) is smaller than a mean free path of a recoil electron generated in the Compton scattering of an electromagnetic radiation. The processing unit (12) specifies and incidence direction of the electromagnetic radiation based on a recoiling direction to which the recoil electron recoils. In this way, an electron tracking-type Compton camera is realized which confines the incidence direction of the electromagnetic radiation by using the recoiling direction of the recoil electron in a Compton camera using a semiconductor detector.