PURPOSE: To easily sample a target colony among connecting colonies by sampling the image of a culture medium where plural colonies are transplanted as image data and deciding whether or not a colony to be transplanted is a connecting colony.

CONSTITUTION: A solid-state image pickup camera 2 incorporates a two-dimensional image sensor and an amplifying circuit and sends an obtained image as an analog signal to an image buffer 12 after A/D conversion 11. Then, data in the image buffer 12 is transferred to a memory 15 through a bus 13 under the control of a microprocessor (MPU) 14. Then, a connecting colony decision program 15b in the memory 15 decides whether or not a reference colony is a connecting colony. Then, a circle approximating program 15c finds the coordinates of the center of each colony. Further, a colony sampling position determining program 15d determines the sampling position of the colony and moves a transplanting stylus to sample the colony. Consequently, the target colony is easily sampled from connecting colonies.