At the PNPI there is the unique setup for the production of the polarized muons which is the only µSR-installation in operation in Russia ( µSR is the Muon Spin Rotation or Muon Spin Resonanse or the Muon Spin Relaxation)   [1].
This equipment allow to carry out the investigation of the varions materials in the temperature range from 10 K to 300 K and in the external transverse and longitudinal magnetic fields (with respect to the muon spin direction). It should be noted that the setup under consideration is be able to compete with the analogous ones in the worldwide scientific centers (PSI and TRIUMF).
       The samples of the studyed materials (solid, liquid or friable) are enclosed into the special cryostat where the necessary temperature can be set and stabilized.
       Now one carries out the number of investigations as follows [2]:

1. The effects of magnetism in the materials with the memory of shape (in the samples of the copper-manganese alloys Cu_1-xMn_x – [3].
2. The random competting interaction in the alloys
   Fe_1-xNi_xСr [4];    and (Pd_0,984Fe_0,016)_0,95Mn_0,05; [5].
3. The mutual influence of ferroelectricity and ferromagnetism:
   • in the rare earth manganites (HoMnO₃, YMnO₃, TbMnO₃) [6],   [x];
   • in the alloyeged manganites La_1-xA_xMnO₃ (A=Ca,Sr);
   • in the rare earth manganates RMn₂O₅ (R= Eu, Gd) [ 7, 8 , 9 ; 10 ];
   • in the rare earth orthoferrites RFeO₃ (R=Ho, Y);
   • in the alloyeged rare earth manganates (multiferroics)    R(1-х)Ce_xMn₂O₅ (R=Eu,Gd) [y]  и Tb_0.95Bi_0.05MnO₃ [z];
4. The properties of the nanostructure materials (the ferroliquid which is the solution of the nanodispersial    Fe₃O₄ or Fe₂CoO₄– magnetite in the D₂O(H₂O) - water with the stabilizing surface-active substance [ 11, 12, 13 , 14 ];   making use of the different concentrations and sizes of granules [15].
5. The segnetomagnetic solid solutions    (1-x)Pb(Fe_2/3W_1/3)O₃ + xPbTiO₃.
6. The control of quality of the industrial steels (of the magnetic texture and the magnetic properties during the production process).
7. Measuring the characteristics of muonium behavior in time (if muonium is formed in the sample under investigation), which will allow the purity of semiconductor materials to be determined up to an impurity content level of ~10^-8 - 10^-9.