Provided is a phased array antenna which can be used in the millimeter wave band and whose cost is lower than that of a conventional phased array antenna. The phased array antenna (1) includes: an optical modulator (OM) configured to generate a signal light beam SL by carrying out intensity modulation on a carrier light beam CL by use of a sum signal VIF+LO(t), the sum signal VIF+LO(t) being obtained by adding an intermediate frequency signal VIF(t) and a local signal VLO(t); and a time delay device (TD) configured to generate delayed signal light beams SL′1, SL′2, . . . and SL′n by imparting time delays Δt1, Δt2, . . . and Δtn to the signal light beam SL. Each feeding circuit (Fi) generates, from a corresponding delayed signal light beam SL′i, a delayed radio frequency signal VRF(t−Δti) to be supplied to an antenna element (Ai).