A phase shifter includes: a first substrate; a signal electrode and a reference electrode on at least one side of an extension direction of the signal electrode; a first insulating layer covering the reference and signal electrodes; and at least one phase controlling unit above the first insulating layer. Each phase controlling unit includes a main body portion and at least one connection portion. Orthogonal projections of the main body portion and the signal electrode on the first substrate at least partially overlap each other. The main body portion and the first insulating layer have a gap therebetween, and the connection portion is connected between the main body portion and a portion of the first insulating layer covering the reference electrode. The main body portion includes first sub-electrodes short-circuited with each other, and at least some of the first sub-electrodes are connected to a same connection portion.