  We study the effect of fluctuations on the {\bf ac} conductivity of a layered
superconductor both for $c$-axis and $ab$-plane electromagnetic wave
polarizations. The fluctuation contributions of different physical nature and
signs (paraconductivity, Maki-Thompson anomalous contribution, one-electron
density of states renormalization) are found to be suppressed by the external
field at different characterisitic frequencies ($ \omega_{\rm AL}\sim T-T_{\rm
c}$, $\omega_{\rm MT} \sim \max\{ T-T_{\rm c}, \tau_{\varphi}^{-1}\}$, $
\omega_{\rm DOS} \sim \min\{T,\tau ^{-1}\}$ for the $2D$ case). As a result the
appearance of the nonmonotonic frequency dependence (pseudogap) in the infrared
optical conductivity of HTS film is predicted. The effect has to be especially
pronounced in the case of the electromagnetic field polarization along
$c$-axis.
