An infrared solid-state imaging device with unit detecting sections in a matrix form, wherein the unit detecting section includes: an infrared light guiding layer; a first reflecting layer on the infrared light guiding layer; an infrared light detecting section on the first reflecting layer, the infrared light detecting section including an infrared light absorbing layer and upper and lower contact layers; and first metal wiring connected to the upper contact layer, wherein a side wall of the unit detecting section is inclined at an angle smaller than 45° to a normal direction, to form a groove between the adjacent unit detecting sections, a first insulating layer is provided on the side wall of the unit detecting section and second metal wiring is provided on the first insulating layer, and a refractive index of the first reflecting layer is lower than that of the lower contact layer.