To establish an insect factory for mass production of useful substances using silkworms, the author developed a silkworm hemolymph collection system to efficiently collect hemolymph from 5th-instar larvae of silkworms, Bombyx mori. The system automatically performs the serial processes of feeding silkworm larvae to the system, incision, collection of hemolymph, and removal of silkworms after hemolymph collection. This system consists primarily of a silkworm feeder, a conveyer chain with holders for the transport of silkworms, a CO₂ laser for infrared laser beam incision of silkworms, a container for hemolymph collection, and two coolers. The hemolymph collection from 4 and 5-day 5th-instar silkworm larvae anesthetized at low temperature could be collected continuously in less than 2.5 min per larva, giving a good prospect for a one-man operation. The amount of hemolymph was 12-13% of the silkworm larva body weight.