A molecular detection apparatus 1 according to an embodiment includes: a collection unit collecting detection target gas containing molecules to be detected; a detector including a detection cell having an organic probe provided at a sensor unit, the organic probe capturing the collected molecule to be detected; and a discriminator discriminating the molecule to be detected by a detection signal generated by the molecule being captured by the organic probe. The detection cell has the organic probe containing a phosphonic acid structure or phosphoric acid structure.