PURPOSE: To improve S/N at a frequency below the shielding frequency without deteriorating light-receiving-and-analyzing capability, by expanding at immediately under a light-shielding membrane a contacting width between a semiconductor member, which forms a carrier travelling section, and an electrode.

CONSTITUTION: A semiconductor member 1 which forms a carrier travelling section 6 is formed in a H-shape configuration, and a part of the center section is shaped up by a light-shielding membrane 4. An extended section having a width larger than width d of a light-receiving area of the semiconductor member 1, that is, both ends of the carrier travelling section 6 are electrically connected to electrodes 3 which are in surface-to-surface contact with the ends. As the electrodes 3 are made to have the same width as those of the both ends of the carrier travelling section 6, the width of the electrodes 3 is to have a large dimension at immediately under the light-shielding membrane 4.