A phased array antenna comprising: a front plate on which a flow path through which coolant flows is formed; a plurality of blocks including a plurality of slices that includes a plurality of transmitters and a circuit board configured tc distribute a power to the transmitters to control operation and to control a passing phase of a high-frequency signal, and a bus board to distribute a power, a control signal, and a high-frequency signal to the plurality of slices , the blocks being held on a first face of the front plate ; a plurality of power sources to supply power to the blocks , the power sources being held on the first face of the front plate ; an antenna element layer in which a plurality of antenna elements are arrayed, the antenna element layer being held on a second face on the back of the first face of the front plate ; and a high-frequency signal wiring layer including high-frequency signal wiring through which a high-frequency signal to the plurality of antenna elements passes, the high-frequency signal wiring layer being held on the second face of the front plate , wherein the front plate has a through hole , and the transmitters include a connector electrically connected to the high-frequency signal wiring via the through hole , characterized in that the high-frequency signal wiring is shifted in an in-plane direction of the front plate in the high-frequency signal wiring layer , a pitch (P 1 ) between the antenna elements is shorter than both a pitch (P 2 ) of the slices of adjacent blocks and a pitch (P 3 ) of the slices within the block 6, and the pitch (P 2 ) between the plurality of slices of the adjacent blocks is independent of the pitch (P 1 ) between the plurality of antenna elements . a front plate on which a flow path through which coolant flows is formed; a plurality of blocks including a plurality of slices that includes a plurality of transmitters and a circuit board configured tc distribute a power to the transmitters to control operation and to control a passing phase of a high-frequency signal, and a bus board to distribute a power, a control signal, and a high-frequency signal to the plurality of slices , the blocks being held on a first face of the front plate ; a plurality of slices that includes a plurality of transmitters and a circuit board configured tc distribute a power to the transmitters to control operation and to control a passing phase of a high-frequency signal, and a bus board to distribute a power, a control signal, and a high-frequency signal to the plurality of slices , the blocks being held on a first face of the front plate ; a plurality of power sources to supply power to the blocks , the power sources being held on the first face of the front plate ; an antenna element layer in which a plurality of antenna elements are arrayed, the antenna element layer being held on a second face on the back of the first face of the front plate ; and a high-frequency signal wiring layer including high-frequency signal wiring through which a high-frequency signal to the plurality of antenna elements passes, the high-frequency signal wiring layer being held on the second face of the front plate , wherein the front plate has a through hole , and the transmitters include a connector electrically connected to the high-frequency signal wiring via the through hole , characterized in that the high-frequency signal wiring is shifted in an in-plane direction of the front plate in the high-frequency signal wiring layer , a pitch (P 1 ) between the antenna elements is shorter than both a pitch (P 2 ) of the slices of adjacent blocks and a pitch (P 3 ) of the slices within the block 6, and the pitch (P 2 ) between the plurality of slices of the adjacent blocks is independent of the pitch (P 1 ) between the plurality of antenna elements . <EOS>