To completely release an ejector pin product without providing a new driving source on the side of a resin sealing device.

This resin sealing mold is provided with an upper mold chase block 7 and a lower mold chase block 8 used for forming a product, two ejector pins 6 which are used to release a product from the resin sealing mold, a pin plate 4 which is used to hold the ejector pins 6, a knock-out plate 2, a pin plate 4 and two prings 5 used to operate the knob-out plate 2. A sub-plate 10 is provided between a spring 5 and the lower mold chase block 8, and a return spring 11, having the recoiling force weaker than the spring 5, is provided between the sub-plate 10 and the lower mold chase block 8.