A medical apparatus (1, 1A-E) comprising: an ultrasound radiating member; a signal generator adapted to produce a drive signal for driving the ultrasound radiating member; the ultrasound radiating member being adapted to, in response to the drive signal from the signal generator, to radiate an ultrasound wave into an object to be examined, the ultrasound wave having a plurality of frequency components different from each other; and a light radiating member adapted to radiate light into a region within the object, at a predetermined time immediately after the completion of radiation of the ultrasound wave, such that the ultrasound wave has already been radiated into the region at said predetermined time; characterized by a light receiving member (27, 28) adapted to receive light reflected and scattered in the region in response to the radiated light from the light radiating member; and a calculator (6, 7) configured to: receive as an input: a spectral signal for providing a spectral distribution of the light received by the light receiving member (27, 28); and the drive signal for providing a spectral distribution of the ultrasound wave radiated by the ultrasound radiating member, calculate a Doppler shift amount f d1, f d2,... f dN in a frequency of the reflected light indicative of a reflected and a scattered state of the radiated light in the region based on the spectral distribution of the light received by the light receiving member (27, 28); calculate scattering components of the reflected light based on said spectral distribution of the light received by said light receiving member (27, 28) and said spectral distribution of the ultrasound wave radiated by the ultrasound radiating member, said spectral distribution having frequencies f us1, f us2,... f usN, wherein the frequency ratios f d1/ f us1, f d2 / f us2,... f dN /f usN serve as said scattering components; and calculate absorption components corresponding to intensities of the scattering components at each frequency ratio. an ultrasound radiating member; a signal generator adapted to produce a drive signal for driving the ultrasound radiating member; the ultrasound radiating member being adapted to, in response to the drive signal from the signal generator, to radiate an ultrasound wave into an object to be examined, the ultrasound wave having a plurality of frequency components different from each other; and a light radiating member adapted to radiate light into a region within the object, at a predetermined time immediately after the completion of radiation of the ultrasound wave, such that the ultrasound wave has already been radiated into the region at said predetermined time; characterized by a light receiving member (27, 28) adapted to receive light reflected and scattered in the region in response to the radiated light from the light radiating member; and a calculator (6, 7) configured to: receive as an input: a spectral signal for providing a spectral distribution of the light received by the light receiving member (27, 28); and the drive signal for providing a spectral distribution of the ultrasound wave radiated by the ultrasound radiating member, calculate a Doppler shift amount f d1, f d2,... f dN in a frequency of the reflected light indicative of a reflected and a scattered state of the radiated light in the region based on the spectral distribution of the light received by the light receiving member (27, 28); calculate scattering components of the reflected light based on said spectral distribution of the light received by said light receiving member (27, 28) and said spectral distribution of the ultrasound wave radiated by the ultrasound radiating member, said spectral distribution having frequencies f us1, f us2,... f usN, wherein the frequency ratios f d1/ f us1, f d2 / f us2,... f dN /f usN serve as said scattering components; and calculate absorption components corresponding to intensities of the scattering components at each frequency ratio. receive as an input: a spectral signal for providing a spectral distribution of the light received by the light receiving member (27, 28); and the drive signal for providing a spectral distribution of the ultrasound wave radiated by the ultrasound radiating member, a spectral signal for providing a spectral distribution of the light received by the light receiving member (27, 28); and the drive signal for providing a spectral distribution of the ultrasound wave radiated by the ultrasound radiating member, calculate a Doppler shift amount f d1, f d2,... f dN in a frequency of the reflected light indicative of a reflected and a scattered state of the radiated light in the region based on the spectral distribution of the light received by the light receiving member (27, 28); calculate scattering components of the reflected light based on said spectral distribution of the light received by said light receiving member (27, 28) and said spectral distribution of the ultrasound wave radiated by the ultrasound radiating member, said spectral distribution having frequencies f us1, f us2,... f usN, wherein the frequency ratios f d1/ f us1, f d2 / f us2,... f dN /f usN serve as said scattering components; and calculate absorption components corresponding to intensities of the scattering components at each frequency ratio.