A welding camera (1) is constructed with: a lens (11) for focusing incident light; an optical filter (12) that comprises a neutral density filter for reducing the amount of the incident light, an ultraviolet cut filter for cutting ultraviolet rays, and a green band-pass filter for transmitting green light; a CMOS imaging unit (13) that has a wide dynamic range function, and detects the light which has passed the optical filter (12); a video signal processing unit (14) that has an automatic gain control function and a digital signal processor, and outputs an image signal, which covers a range of a low-intensity dark part to high-intensity arc light, to a display unit on the basis of an electric signal that is input from the CMOS imaging unit (13).