To provide a probe capable of not only securing full bonding strength by forming a solder bump not only on the front surface of the probe but also on its back surface for increasing bonding area, and to provide a probe card to which such a probe is mounted.

The probe having a three-layer structure in which outer layers are arranged on both sides of an intermediate layer is constituted of a mounting part in which a solder bump is formed at a bottom part; an arm part extending from the mounting part; and a tip part provided for the tip of the arm part. The bottom surface of the mounting part is provided with a protrusion part in which the intermediate layer protrudes more than the two outer layers, and the solder bump is formed in such a way as to surround the protrusion part and to cover part of side surfaces and part of the front and back surfaces of the mounting part.