An electret having a high surface charge density, is provided and along with an electrostatic induction conversion device including such an electret. In some embodiments, the electret includes a laminate having a layer (A) containing a polymer compound (a) having a relative dielectric constant of from 1.8 to 3.0 and a layer (B) containing a polymer compound (b) or inorganic substance (c) having a relative dielectric constant higher than the polymer compound (a). The difference between the relative dielectric constant of the polymer compound (b) or inorganic substance (c) and the relative dielectric constant of the polymer compound (a) is at least 0.3. The layer (A) is disposed on the outermost surface on a side opposite to the side where electric charge is injected at the time of injecting electric charge into the laminate to form the electret; and the layer (B) has a thickness of at least 1 μm.