A microchannel array according to the present invention includes a first substrate 1, and a second substrate 11 bonded to the first substrate 1. Two sets, that is, a set of a first through-hole 9, a first recess 7, and a first groove 8 and a set of a second through-hole 4, a second recess 2, and a second groove 3 are formed on the first substrate 1. The different sets are separated by a partition 5. A cell differentation/proliferation speed after micro-injection can be increased by using such microchannel array.