The rotational structure of the bending fundamental v5 of monofluoroacetylene around 366 cm -1 was investigated. The measurements were performed using a Michelson type Fourier spectrometer with a resolution of about 0.05 cm -1 . The values B0=0.32373 cm -1 , a5-= - 6.00 x 10 -4 cm -1 , q5= 6.3 x 10 -4 cm -1 and D = 11.2 x 10 -8 cm -1 were obtained from the analyses of the P-, Q-, and R-branches. In addition, some hot bands accompanying the fundamental were studied.