To provide a device for reducing stray light made incident on a detection element in a hand-held scanner device.

This stray light baffle 10 for reducing the amount of stray light 70 and 70' made incident on a detector 50 is provided with a main body part 60 and an attaching pad part 62, and the stray light baffle 10 is fixed to an attaching surface 88 with a photosetting adhesive material 86 by the attaching pad part 62. The attaching surface 88 is positioned adjacent to the detector 50 so as to have the main body part 60 inserted between the detector 50 and the source of the stray light 70 and 70', when the photosetting adhesive material 86 is set in reaction to setting light made incident on it, and the stray baffle 10 is attached to the attaching surface 88 and the main body part 60 and the attaching pad part 62 of the stray light baffle 10 transmit the setting light and interrupt the stray lights 70 and 70'.