A slight volume collector adapted to collect a sample liquid with slight volume and be assembled to a detecting device is provided. The slight volume collector includes a body and an extension part. The extension part extends outward from the body and protrudes from the body. The extension part has a through hole, and the through hole passes through the extension part and corresponds to the body. The sample liquid is adapted to be adhered to and arranged in the through hole due to capillarity, and a volume of the sample liquid is substantially equal to a capacity of the through hole.