The effect of macroscopic quantum tunnelling (MQT) in fine magnet particles has been investigated, using quasiclassical approach (WKB) with the micromagnetic method of description of magnetic moments movement Mr(t) orientation in relation to 'light' axis. The probability of macroscopic tunnel transition of Mr(t) is determined for the crystals of various syngony. In the case of the ferromagnetic particles the influence of magnetic fields on W is taken into consideration. The results of the work are confirmed by experimental measurements of superparamagnetic properties of the ferromagnetic microparticles ensemble in the non-magnetic matrix, separated enough from each other.