A measuring apparatus for performing detection of a signal which varies with displacement of an object and measurement of the displacement, the apparatus comprising: a clock generator configured to generate, in synchronization with and based on a request signal for requesting measurement data, a first clock signal having a cycle shorter than a cycle of the request signal; a detector configured to perform the detection with respect to each cycle of the first clock signal; an operation device configured to obtain the measurement data based on an output of the detector; characterized in that the apparatus further comprises: a correction device configured to obtain a displacement amount of the object per unit time based on a plurality of the measurement data (P2_10, P3_1, P4 1) from the operation device, and to correct the measurement data (P4_1) based on the obtained displacement amount and a time difference (tsp) between a time point at which measurement of first measurement data has been started before the request signal for the first measurement is received and a time point at which the request signal for the first measurement data is received; wherein the cycle of the request signal includes a first term in which the request signal includes a plurality of clock signals and a second term (timeout) in which the request signal is a constant value; and wherein the clock generator includes a counter and a phase synchronizing device, the counter is configured to count a clock signal of the plurality of clock signals included in the request signal, and the phase synchronizing device is configured to output, based on an output of the counter, the first clock signal in synchronization with the clock signal of the plurality of clock signals included in the request signal in the first term and output, continually in the second term after the first term, the first clock signal output in the first term. a clock generator configured to generate, in synchronization with and based on a request signal for requesting measurement data, a first clock signal having a cycle shorter than a cycle of the request signal; a detector configured to perform the detection with respect to each cycle of the first clock signal; an operation device configured to obtain the measurement data based on an output of the detector; characterized in that the apparatus further comprises: a correction device configured to obtain a displacement amount of the object per unit time based on a plurality of the measurement data (P2_10, P3_1, P4 1) from the operation device, and to correct the measurement data (P4_1) based on the obtained displacement amount and a time difference (tsp) between a time point at which measurement of first measurement data has been started before the request signal for the first measurement is received and a time point at which the request signal for the first measurement data is received; wherein the cycle of the request signal includes a first term in which the request signal includes a plurality of clock signals and a second term (timeout) in which the request signal is a constant value; and wherein the clock generator includes a counter and a phase synchronizing device, the counter is configured to count a clock signal of the plurality of clock signals included in the request signal, and the phase synchronizing device is configured to output, based on an output of the counter, the first clock signal in synchronization with the clock signal of the plurality of clock signals included in the request signal in the first term and output, continually in the second term after the first term, the first clock signal output in the first term. a correction device configured to obtain a displacement amount of the object per unit time based on a plurality of the measurement data (P2_10, P3_1, P4 1) from the operation device, and to correct the measurement data (P4_1) based on the obtained displacement amount and a time difference (tsp) between a time point at which measurement of first measurement data has been started before the request signal for the first measurement is received and a time point at which the request signal for the first measurement data is received; wherein the cycle of the request signal includes a first term in which the request signal includes a plurality of clock signals and a second term (timeout) in which the request signal is a constant value; and wherein the clock generator includes a counter and a phase synchronizing device, the counter is configured to count a clock signal of the plurality of clock signals included in the request signal, and the phase synchronizing device is configured to output, based on an output of the counter, the first clock signal in synchronization with the clock signal of the plurality of clock signals included in the request signal in the first term and output, continually in the second term after the first term, the first clock signal output in the first term.