An electromagnetic wave transmissive cover includes: a base made of a dielectric material and having transmissiveness to electromagnetic waves; and a reflection hindering layer laminated on at least one of two surfaces of the base in a travel direction of the electromagnetic waves, made of a dielectric material, having transmissiveness to the electromagnetic waves, and hindering reflection of the electromagnetic waves. A wavelength of each electromagnetic wave in the reflection hindering layer is referred to as λ2 and 2π/λ2 is set as a phase constant β2. An amount of deviation between a phase of a reflected wave reflected on the front interface of the reflection hindering layer in the travel direction and a phase of a reflected wave reflected on the rear interface is referred to as a phase deviation amount β. Thickness L2 of the reflection hindering layer is set to β/β2.