An imaging mechanism and an endoscope apparatus include: an image sensor including a sensor face and a plurality of input/output leads, a holding member having a sensor contact face, a circuit board that is secured to an outer face of an opposite side of the holding member to the sensor contact face, and a contact-point part disposed on a side face of the circuit board intersecting with a mount face, and in a region where the outline of the circuit board is inside the outline of the holding member. At least one of the holding member and the circuit board includes a relay wiring part which the contact-point part and at least one of the input/output leads are electrically connected to.