To increase the reaction efficiency of a photocatalyst, and to widen a photoreaction area in the photocatalyst.SOLUTION: A deodorization module 1 (photocatalyst device) comprises a light source 13 having an LED lamp 12 arranged for irradiation with light in a predetermined direction, and a reflection plate 30 for reflecting the light irradiated with from the light source 13. An air flow path 50 for flowing air in a direction crossing the irradiation direction of the light from the light source 13 is disposed between the light source 13 and the reflection plate 30, and a photocatalyst member 20 is disposed along the direction of air flow in the air flow path 50. The photocatalyst member 20 uses as a carrier a substrate 22 having a plurality of openings 24 through which the light irradiated with from the light source 13 passes from a front surface 20f side to a back surface 20b side, and supports the photocatalyst 23 on the front surface 20f and the back surface 20b of the substrate 22.SELECTED DRAWING: Figure 1【課題】光触媒の反応効率を高くし、光触媒における光反応領域を広くすること。【解決手段】脱臭モジュール１（光触媒装置）は、予め決められた方向に光を照射するように配置されたＬＥＤランプ１２を備える光源１３と、光源１３から照射された光を反射する反射板３０とを備え、光源１３と反射板３０との間に、光源１３からの光の照射方向を横切る方向に空気を流す空気流路５０を配置し、この空気流路５０内に、空気の流れの方向に沿って光触媒部材２０を配置している。光触媒部材２０は、光源１３から照射された光を前面２０ｆの側から背面２０ｂの側へと通過させる複数個の開口２４を有する基材２２を担体として、この基材２２の前面２０ｆ及び背面２０ｂに光触媒２３を担持させている。【選択図】図１
