A scanning antenna (1000) in which antenna units (U) are arranged, the scanning antenna including: a first dielectric substrate (1); a TFT substrate (101) including TFTs, gate bus lines, source bus lines, and patch electrodes (15); a slot substrate (201) including a second dielectric substrate (51), and a slot electrode (55) formed on a first main surface of the second dielectric substrate; a liquid crystal layer (LC) provided between the TFT substrate and the slot substrate; and a reflective conductive plate (65) provided opposing a second main surface of the second dielectric substrate (51) opposite to the first main surface via a dielectric layer (54). The slot electrode includes slots arranged corresponding to each of the patch electrodes, and the second dielectric substrate (51) and the slot electrode (5) further include an adhesive layer (92) formed therebetween from a thermosetting type or photocurable type adhesive material.