An endoscope includes at least one lens having a circular exterior shape in a direction perpendicular to an optical axis, an image sensor that has a square exterior shape in the direction perpendicular to the optical axis, and has one side whose length is same as length of a diameter of the lens, a sensor cover that has a square exterior shape in the direction perpendicular to the optical axis, and has one side whose length is same as one side length of the image sensor, a bonding resin portion that fixes the sensor cover to the lens, the optical axis of the lens coinciding with a center of the imaging area.