An electromagnetic wave transmission device according to the present invention includes: a transmission unit that has, in voltage-current characteristics, a local maximum value and a local minimum value located on a higher voltage side than the local maximum value and transmits an electromagnetic wave indicating a modulation signal; and a modulation unit which modulates an acquired digital signal to the modulation signal using first voltage values of two or more levels in a first voltage region, which is equal to or greater than a voltage of the local maximum value and is equal to or less than a voltage of the local minimum value, and a second voltage value in a second voltage region, which is less than the voltage of the local maximum value, and a third voltage value in a third voltage region, which is on a higher voltage side than the voltage of the local minimum value. A first signal which transits to any one voltage value of the first voltage values from any voltage value in the first voltage region via the second voltage value and a second signal which transits to the any one voltage value from the any voltage value via the third voltage value are the same signals. The modulation unit selects, out of the first signal and the second signal, the signal having a smaller total transition potential difference.