A pyroelectric sensor array is attachable on a circuit board. The pyroelectric sensor array comprises a pyroelectric board and a plurality of pyroelectric elements formed on the pyroelectric board. The pyroelectric board has a connection surface configured to be placed on the circuit board. The pyroelectric elements contains a peripheral pyroelectric element arranged at a peripheral portion of the pyroelectric board in a predetermined arranging direction and a central pyroelectric element arranged at a central portion of the pyroelectric board. Each of the pyroelectric elements has two adjacent connection electrodes formed on the connection surface. An electrostatic capacity between the two connection electrodes of the peripheral pyroelectric element is larger than an electrostatic capacity between the two connection electrodes of the central pyroelectric element.