An apparatus and method for detecting an error occurring when an application program is executed in a computer environment is provided. The error detection apparatus may measure a deterministic progress index (DPI) and a program counter (PC) value when an instruction is executed, set, as a verification set, a DPI and a PC value measured when the instruction is executed without causing an error, set, as a measurement set, the DPI and the PC value measured when an instruction is executed, and detect a runtime error of the instruction by comparing the measurement set to the verification set.