There is a strong demand for detection of small contaminants in food and pharmaceutical medicines. High-Tc SQUID detection systems for a metallic contaminant in foodstuffs and drugs are developed for safety. We developed two systems; one large system is for meat blocks and the other small system is for powdered drugs or packaged foodstuffs. Both systems consist of SQUID magnetometers, a permanent magnet for magnetization and a belt conveyer. All the samples were magnetized before measurements and measured by high Tc SQUIDs. As a result, we successfully measured small syringe needles with length of 2mm in a meat block and a stainless steel ball as small as 0.3mm in diameter.