This invention is to provide a liquid adhesive of the present invention can be adhered and cured at a relatively low temperature and have sufficient heat resistance and reliability, etc., and an adhesive tape using the same.The liquid adhesive of this invention is obtainable by dissolving (a) a piperazinylethylaminocarbonyl-containing butadiene-acrylonitrile copolymer having a weight average molecular weight of 10,000-200,000, an acrylonitrile content of 5-50% by weight, and an amino equivalent of 500-10,000, represented by the following formula (I): ##STR1## wherein, k, m, and n are molar ratios and taking n as 1, k is a number of 3-175, and m is a number of 0.3 to 93; and (b) a compound having at least two maleimide groups, the ratio of component (b) based on 100 parts by weight of component (a) being in the range of 10 to 900 parts by weight. This is applied to one or both surfaces of a heat resistant film or one surface of a release film to form an adhesive layer, thereby obtaining an adhesive tape for electronic parts.