In this study, a new diac-like switch using GaAs double triangular barrier structures (DTBS) prepared by molecular beam epitaxy (MBE) has been fabricated and demonstrated. Unique bidirectional current-voltage ( I- V) characteristics between 300 and 77 K were realized for the first time. Large on/off voltage differences and control efficiency were observed in both directions. Based on I- V measurements, the operation mechanism of the diac-like switch was analyzed and is discussed in detail using an equivalent circuit approach. A temperature-dependent effect on the switching voltage, VS, and holding voltage, VH, was also investigated.