A phosphor has a plate-shaped phosphor, a joining-member, and a light collecting optical member. The light collecting optical member has at least one convex surface and is fixed to the plate-shaped phosphor by the joining-member. The joining-member forms a fillet shape between a surface of the plate-shaped phosphor to which the light collecting optical member is joined and a convex surface of the light collecting optical member. In a case where a height of the fillet shape from the surface of the plate-shaped phosphor to which the light collecting optical member is joined is set as a height X and a maximum distance of the light collecting optical member from the surface of the plate-shaped phosphor to which the light collecting optical member of is joined is set as a maximum distance Y, the height X is equal to or less than ⅔ of the maximum distance Y.