Dynamics of semiconductor microcavity modes in ZnSe- metal structure was investigated by femtosecond pump- supercontinuum probe spectroscopy in wide spectral region 300 - 800 nm. The powerful laser pump pulse excites electrons of metal (i.e. boundary of the microcavity) and of ZnSe layer (by two-photon absorption and absorption of second-harmonics generated photon). Photoinduced changes of dielectric function of metal transform the boundary condition. It leads to shift of frequencies of cavity modes to red region of spectrum. Another contribution to change of boundary condition is connected with tunneling of excited electrons through Schottky electron barrier into ZnSe layer. The generation of coherent phonon oscillations (LO-phonon mode 250 cm-1 and TO-phonon mode 200 cm-1) in ZnSe was detected.