An imaging element and device configured for reduced image quality deterioration are disclosed. In one example, a pixel unit of the imaging element includes a selection transistor and an amplification transistor each constituted by a multigate transistor. The selection transistor and amplification transistor may be a FinFET that includes a silicon channel having a fin shape. Moreover, gates of the selection transistor and the amplification transistor may be formed on an identical silicon channel having a fin shape. Furthermore, for example, an ion having a smaller thermal diffusivity than a thermal diffusivity of boron or phosphorous is injected into the silicon channel of the selection transistor. In addition, for example, a work function of a material of a gate electrode of the selection transistor is different from a work function of a material of a gate electrode of the amplification transistor.