The present disclosure provides a phase shifter and an antenna. The phase shifter includes a first substrate and a second substrate opposite to each other; a signal transmission structure between the first substrate and the second substrate, wherein the signal transmission structure is configured to transmit a microwave signal; a phase shifting structure between the first substrate and the second substrate, wherein the phase shifting structure is configured to adjust a phase of the microwave signal; wherein the signal transmission structure includes a connection structure on the signal transmission structure; the signal transmission structure is connected to the phase shifting structure through the connection structure; the phase shifter further includes: an isolation structure between the first substrate and the second substrate; wherein the isolation structure is on the connection structure and separates a dielectric layer of the signal transmission structure from a dielectric layer in the phase shifting structure.