Provided is a microchip that can achieve a favorable bonding state in the bonding portion between first and second substrates even if the microchip is large in size.A microchip includes a first substrate made of a resin and a second substrate made of a resin, the first substrate and the second substrates being bonded to each other, and a channel surrounded by a bonding portion between the first substrate and the second substrate is formed by a channel forming step formed at least in the first substrate. Further, a noncontact portion is formed to surround the bonding portion, and an angle 01 formed between a side wall surface of the channel forming step and a bonding surface continuous therewith satisfies θ1>90°.