Disclosed is an illumination device wherein a placement member (5) has an abutment surface (27a) which abuts with the underside surface of a LED module (3) and a raised portion (5a) which is raised around the abutment surface (27a) in the thickness direction of the LED module (3) to restrict sliding of the LED module (3); an attachment member (6) is composed of a plate-shaped member having a spring property, and is provided with a pair of planar portions (43, 43) disposed around the abutment surface (27a) of the placement member (5) and at positions opposite to each other, and extended plate portions (44, 44) which extend from the planar portions (43, 43) toward the abutment surface (27a) and which abut with the top surface of a substrate (17); and the planar portions (43, 43) of the attachment member (6) are fixed at positions lower than the surface of the substrate (17) of the LED module (3), so that the portions of the planar portions (43, 43), which extend from the fixed portions to the extended plate portions (44, 44), are elastically deformed to press the substrate (17) toward the placement member (5).