The transformation of Si diamond cubic structure into β-Sn metallic phase under indentation takes place due to the high pressures created during loading at 8-11 GPa and then during unloading when the material is depressurized BC8/R8 and amorphous phases are formed that can be visualized on the indentation load-displacement curve as a “pop-out” or “elbow” events respectively (Fig. 1). In this work it was investigated the influence of loading holding time under the dynamic indentation on the mean contact pressures at which the “pop-out” and “elbow” events take place. The contact pressure was estimated from the indention curve using the method of Novikov et al [1]. The calculation procedure was automatized by a special written computer program, which make it possible to analyze a large amount of measurements. The analysis of obtained results showed that with increase of loading holding time the contact pressures of both “elbow” and “pop-out” formation decrease. It was assumed that this result is caused by the deviatoric components of stresses in the indentation zone, the influence of which could increase during longer holding time in comparison with ordinary one and which can lead to the lowering of stresses necessary for the phase transformation. It was observed as well that with increase of holding time the “pop-out” is replaced in some cases by the “elbow” effect, the extending of which along the penetration depth (h) is smaller than that of “pop-out” (Fig.1). This is consistent with Raman spectra results demonstrating for longer holding time indentations more intensive peaks of 488,8 cm-1 corresponding to amorphous phase of Si.figureFig. 1. Si(100), load-displancement curves of Berkovich indentations, P=100mN; a - holding time is 5s, b - holding time is 900s. Besides, for longer holding time for all used loads (50, 100 and 500mN) the hardness has lower values then for shorter holding time. This is explained by the creep of material, which results in increases of penetration depth and hence, contact area of indentation, the load values remaining the same that by definition signifies the decrease of hardness values. [1] N.V. Novikov, S.N. Dub, Y.V. Milman, I.V. Gridneva and S.I. Chugunova. Journal of Superhard Materials (Sverkhtverdye Materialy) 18 (1996) 32.