The capacitive response of deep Fe acceptors in a semi‐insulating n‐type Fe‐doped InP Schottky barrier has been investigated. The capacitance‐voltage (C‐V) and conductance‐voltage (G‐V) characteristics over the frequency range 0.06–100 kHz are measured at 300, 317, and 335 K. Great frequency dispersion is observed in C and G. The reverse bias dependencies of C and (G-G0) are shown to be very weak at high frequencies, where G0 is the dc conductance. As measuring frequency is lowered, (G-G0) decreases but C increases considerably. At low frequencies, the bias dependencies of C and (G-G0) are observed and measured 1/C2 versus reverse bias curves are found to be straight lines. It is shown that at low frequencies, C and (G-G0) take maxima near zero bias and rapidly decrease in a forward bias region. As temperature increases, the frequency region in which such low‐frequency characteristics are found extends more widely into a high‐frequency range. Theoretical calculations of C and (G-G0) are also carried out. The results are compared with experimental ones. Observed variations of C and G with frequency, bias voltage, and temperature are well explained in terms of the delayed response of deep Fe acceptors.