To obtain a pinhole detector capable of detecting a minute pinhole, specifying a pinhole detection position, and efficiently performing detection.

The pinhole detector is provided with a liquid vessel 3 storing liquid W, a specimen continuous immersion means 4 in which a specimen 1 is continuously sent out in a state where an inner pressure is applied by gas and continuously passed in the liquid W of the liquid vessel 3, an imaging element type camera 5 for photographing bubbles produced in the liquid from the pinhole of the specimen 1 passed in the liquid W of the liquid vessel 3, and a bubble detection means comprising an image processor 6 for processing an image signal sent from the camera 5 and detecting the presence of the bubbles. The bubbles produced in the liquid from the pinhole of the specimen 1 are photographed by the imaging element type camera 5 to be processed by the image processor 6 so as to detect the pinhole of the specimen 1. As a result, the detection of the minute bubbles is enabled and the detection of a minute pinhole is enabled. In addition, the efficiency of inspection working is high and a pinhole position can be specified.