A first connection line includes a first tube-side wiring pattern formed on an outer periphery of a measuring tube and connected at one end thereof to a first surface electrode, a first substrate-side wiring pattern formed on a preamplifier substrate and connected at one end thereof to a preamplifier, and a first jumper wire connecting the other end of the first tube-side wiring pattern to the other end of the first substrate-side wiring pattern; and a second connection line includes a second tube-side wiring pattern formed on the outer periphery of the measuring tube and connected at one end thereof to a second surface electrode, a second substrate-side wiring pattern formed on the preamplifier substrate and connected at one end thereof to the preamplifier, and a second jumper wire connecting the other end of the second tube-side wiring pattern to the other end of the second substrate-side wiring pattern.