A terahertz wave temporal waveform acquisition apparatus (1;2;3) comprising: a light source for outputting pulsed light (L 0 ); a branch part (20;80) for branching the pulsed light (L 0 ) output from the light source , outputting one beam of the branched light as pump light (L 1 ), and outputting another beam of the branched light as probe light (L 2 ); a terahertz wave generation element for generating and outputting a terahertz wave (L T ) by receiving as an input the pump light (L 1 ) output from the branch part (20;80); a terahertz wave detection element configured to receive as inputs the terahertz wave (L T ) output from the terahertz wave generation element and passed through or reflected by a measurement object and the probe light (L 2 ) output from the branch part (20;80), and to detect a correlation value between the terahertz wave (L T ) and the probe light (L 2 ); a delay providing medium disposed on an optical path of the terahertz wave (L T ) from the terahertz wave generation element to the terahertz wave detection element , formed of a material of which a refractive index for the terahertz wave (L T ) depends on the temperature, and configured to provide a delay according to the temperature to the terahertz wave (L T ); a temperature adjustment unit configured to adjust the temperature of the delay providing medium to a plurality of different temperature values; and an analysis unit configured to obtain a temporal waveform of an electric field amplitude of the terahertz wave (L T ) input to the terahertz wave detection element based on the correlation value detected by the terahertz wave detection element when the temperature of the delay providing medium is set to each value of the plurality of different temperature values by the temperature adjustment unit . a light source for outputting pulsed light (L 0 ); a branch part (20;80) for branching the pulsed light (L 0 ) output from the light source , outputting one beam of the branched light as pump light (L 1 ), and outputting another beam of the branched light as probe light (L 2 ); a terahertz wave generation element for generating and outputting a terahertz wave (L T ) by receiving as an input the pump light (L 1 ) output from the branch part (20;80); a terahertz wave detection element configured to receive as inputs the terahertz wave (L T ) output from the terahertz wave generation element and passed through or reflected by a measurement object and the probe light (L 2 ) output from the branch part (20;80), and to detect a correlation value between the terahertz wave (L T ) and the probe light (L 2 ); a delay providing medium disposed on an optical path of the terahertz wave (L T ) from the terahertz wave generation element to the terahertz wave detection element , formed of a material of which a refractive index for the terahertz wave (L T ) depends on the temperature, and configured to provide a delay according to the temperature to the terahertz wave (L T ); a temperature adjustment unit configured to adjust the temperature of the delay providing medium to a plurality of different temperature values; and an analysis unit configured to obtain a temporal waveform of an electric field amplitude of the terahertz wave (L T ) input to the terahertz wave detection element based on the correlation value detected by the terahertz wave detection element when the temperature of the delay providing medium is set to each value of the plurality of different temperature values by the temperature adjustment unit . <EOS>