PURPOSE: A method and a device detecting envelope are provided to detect an envelope of a modulated signal with low calculation complexity and simple circuit configuration. CONSTITUTION: A generation unit(810) generates a plurality of sampling signals corresponding to a modulated signal. An extraction unit(820) extracts three or more sampling signals with the same time interval in a plurality of the sampling signals. An identification unit(830) identifies one target sampling signal and the other sampling signal from the extracted sampling signals. A calculation unit(840) calculates an envelope component corresponding to the target sampling signal based on the difference between the component related to the target sampling signal and the component related to the rest sampling signals. A detection unit(850) detects envelope of the modulated signal based on the component of the envelope. [Reference numerals] (810) Generation unit; (820) Extraction unit; (830) Identification unit; (840) Calculation unit; (841) Multiplier; (845) Adder; (850) Detection unit; (860) Control unit
