Provided is an adhesive as follows. The adhesive can bond/secure an adherend to a support with maintaining high adhesiveness during the existence of the need for securing of the adherend to the support, even in a high-temperature environment or in an environment with abrupt temperature change. The adhesive enables debonding of the adherend from the support without breakage of the adherend when the securing becomes unnecessary. The adhesive can be easily removed when remained on the adherend after debonding. The adhesive according to the present invention contains (A) a multivalent vinyl ether compound, (B) a compound including two or more of a constitutional unit represented by Formula (b), and (C) a thermoplastic resin. In the formula, X is selected from hydroxy and carboxy.