To provide an adhesive composition and an adhesive sheet, enabling adhesion at low temperatures, excellent in adhisivity and heat resistance, and useful in circuit boards in particular.

A polyamide resin 80C or higher in glass transition temperature, 0.15 dL/g or higher in logarithmic viscosity and 1,500 MPa or lower in tensile modulus is provided, wherein the amine component or isocyanate component of this polyamide resin contains isophorone residues and/or dicyclohexylmethane residues. An adhesive obtained from the polyamide resin and the adhesive sheet using the adhesive are provided, respectively. Printed circuit boards using the adhesive sheet are also provided.