An encoding device comprising: a first encoder (102, 104), which in operation, encodes a low-band signal among a voice or audio input signal to generate a first encoded signal, and decodes the first encoded signal to generate a low-band decoded signal; a second encoder, which in operation, encodes, on the basis of the low-band decoded signal, a high-band signal having a band higher than that of the low-band signal to generate a high-band encoded signal; an energy calculator, which in operation, calculates an energy of the voice or audio input signal and outputs the calculated energy as quantized band energy, and a first multiplexer, which in operation, multiplexes the quantized band energy, the first encoded signal, and the high-band encoded signal to generate and output an encoded signal, characterized in that the second encoder includes a separating unit (202; 302) that separates, from the low-band decoded signal, a low-band non-tonal signal, which is a non-tonal component of the low-band decoded signal, and a low-band tonal signal, which is a tonal component of the low-band decoded signal, the tonal component being a component that has been quantized by a pulse quantizer, the non-tonal component being a component that has become zero by not having been quantized by a pulse quantizer, a noise adding unit that adds a noise signal to the low-band decoded signal or to the low-band non-tonal signal output from the separating unit, a first bandwidth extending unit that outputs, as lag information, position information regarding a specific band in which correlation between the high-band input signal and the low-band tonal signal becomes maximum, a calculating unit that calculates an energy ratio between a high-band noise component, which is a noise component of the high-band input signal, corresponding to the specific band, and the high-band non-tonal signal obtained by the second bandwidth extending unit, and outputs the calculated ratio as a scaling factor, and a second multiplexer that multiplexes the lag information and the scaling factor as the high-band encoded signal and outputs the high-band encoded signal. a first encoder (102, 104), which in operation, encodes a low-band signal among a voice or audio input signal to generate a first encoded signal, and decodes the first encoded signal to generate a low-band decoded signal; a second encoder, which in operation, encodes, on the basis of the low-band decoded signal, a high-band signal having a band higher than that of the low-band signal to generate a high-band encoded signal; an energy calculator, which in operation, calculates an energy of the voice or audio input signal and outputs the calculated energy as quantized band energy, and a first multiplexer, which in operation, multiplexes the quantized band energy, the first encoded signal, and the high-band encoded signal to generate and output an encoded signal, characterized in that the second encoder includes a separating unit (202; 302) that separates, from the low-band decoded signal, a low-band non-tonal signal, which is a non-tonal component of the low-band decoded signal, and a low-band tonal signal, which is a tonal component of the low-band decoded signal, the tonal component being a component that has been quantized by a pulse quantizer, the non-tonal component being a component that has become zero by not having been quantized by a pulse quantizer, a noise adding unit that adds a noise signal to the low-band decoded signal or to the low-band non-tonal signal output from the separating unit, a first bandwidth extending unit that outputs, as lag information, position information regarding a specific band in which correlation between the high-band input signal and the low-band tonal signal becomes maximum, a calculating unit that calculates an energy ratio between a high-band noise component, which is a noise component of the high-band input signal, corresponding to the specific band, and the high-band non-tonal signal obtained by the second bandwidth extending unit, and outputs the calculated ratio as a scaling factor, and a second multiplexer that multiplexes the lag information and the scaling factor as the high-band encoded signal and outputs the high-band encoded signal.