An imaging unit comprising: a solid state image sensor configured to receive light and perform photoelectric conversion on the light to generate an electric signal; a flexible substrate including one end connected to a light receiving surface of the solid state image sensor, the flexible substrate extending to a surface side opposite to the light receiving surface; a multi-layer substrate connected to a surface of the flexible substrate, the surface of the flexible substrate being a surface to which the solid state image sensor is connected, the multi-layer substrate including connection lands on which a plurality of electronic components (55 to 59) are mounted; and a bump by which connection lands provided on the surface of the flexible substrate and connection lands provided on a surface of the multi-layer substrate facing the surface of the flexible substrate are coupled so that the multi-layer substrate is electrically and mechanically connected to the flexible substrate, wherein the multi-layer substrate includes, on a proximal end side relative to a connection portion between the flexible substrate and the multi-layer substrate on a connection surface to which the flexible substrate is connected, a recessed portion in which at least one of the electronic components (55 to 59) is mounted, a depth of the recessed portion from the connection surface is less than a height of the at least one of the electronic components (55 to 59) mounted in the recessed portion, each electronic component (55 to 59) mounted in the recessed portion on the connection surface of the multi-layer substrate connected to the flexible substrate is configured not to project from a surface of the flexible substrate opposite to the connection surface, cable connection lands are formed on proximal end sides relative to the recessed portion on the connection surface of the multi-layer substrate and a surface of the multi-layer substrate opposite to the connection surface, and a drive signal cable and an image signal cable are connected to the cable connection lands formed on the different surfaces of the multi-layer substrate, respectively. a solid state image sensor configured to receive light and perform photoelectric conversion on the light to generate an electric signal; a flexible substrate including one end connected to a light receiving surface of the solid state image sensor, the flexible substrate extending to a surface side opposite to the light receiving surface; a multi-layer substrate connected to a surface of the flexible substrate, the surface of the flexible substrate being a surface to which the solid state image sensor is connected, the multi-layer substrate including connection lands on which a plurality of electronic components (55 to 59) are mounted; and a bump by which connection lands provided on the surface of the flexible substrate and connection lands provided on a surface of the multi-layer substrate facing the surface of the flexible substrate are coupled so that the multi-layer substrate is electrically and mechanically connected to the flexible substrate, wherein the multi-layer substrate includes, on a proximal end side relative to a connection portion between the flexible substrate and the multi-layer substrate on a connection surface to which the flexible substrate is connected, a recessed portion in which at least one of the electronic components (55 to 59) is mounted, a depth of the recessed portion from the connection surface is less than a height of the at least one of the electronic components (55 to 59) mounted in the recessed portion, each electronic component (55 to 59) mounted in the recessed portion on the connection surface of the multi-layer substrate connected to the flexible substrate is configured not to project from a surface of the flexible substrate opposite to the connection surface, cable connection lands are formed on proximal end sides relative to the recessed portion on the connection surface of the multi-layer substrate and a surface of the multi-layer substrate opposite to the connection surface, and a drive signal cable and an image signal cable are connected to the cable connection lands formed on the different surfaces of the multi-layer substrate, respectively.