We presented terahertz (THz) generation and detection characteristics of an InGaAs epilayer with periodic InAlAs insertion layers (InGaAs-PIL). The peak-to-peak current signal (PPCS) from a THz transmitter with the InGaAs-PIL was three times higher than that of a simple InGaAs epilayer. Moreover, the detection properties of a THz receiver with the low-temperature grown (LT) InGaAs-PIL showed more than twenty-five times higher than that of the LT-InGaAs epilayer. The PPCS of the LT-InGaAs-PIL was significantly improved with increasing the periods of the InAlAs insertion layer.