Provided is an edge-light-type illuminating device wherein formation of a space between a point light source and the end surface of a light guide plate is suppressed, and thermal expansion of the light guide plate is allowed. The edge-light-type illuminating device (1) illuminates a liquid crystal panel from the rear surface, and is provided with: the substantially rectangular light guide plate (2); walls (3) surrounding the light guide plate (2); a plurality of holding sections (4), which are disposed between the respective end surfaces (7) of the light guide plate (2) and the walls (3), and hold the light guide plate (2) inside of the walls (3); and point light source rows (6, 6), each of which is composed of a plurality of point light sources (5) and are disposed along the respective end surfaces (7a, 7b) on the adjacent two sides of the light guide plate (2). Among the holding sections (4), the holding section (4) that faces the point light source row (6) with the light guide plate (2) therebetween is composed of an elastic holding section (4a) having an elastic force.