Studies of the electro-physical properties of n-type semi-insulating indium-doped Cd(Mn)Te crystals with a resistivity ~ (4-5)×10 10 Ohm×cm at T = 300 K were carried out. Structures with both ohmic (In/Cd(Mn)Te/In) and rectifying (Ni/Cd(Mn)Te/In) contacts were fabricated and tested. It was found that in the case of the Ni/Cd(Mn)Te/In structure, the charge transport can be explained by the generation of currents in the space-charge region and the spacecharge limited current (SCLC) at high voltages, while Ohm's law is valid only at the initial section of the volt-ampere (I-V) curve. Calculations of the dependence of the generation current on the voltage according to the Sah-Noyce-Shockley model were performed. For the In/Cd(Mn)Te/In structure, we observed the initial part of the I-V curve obeys Ohm's law, and the SCLCs with participation of deep centers (traps) in the semi-insulating crystal were observed at greater voltages. The concentration of deep centers (Nt ~ 7.4×10 10 cm -3 ) responsible for the trap mechanism in SCLC In/Cd(Mn)Te/In structures was calculated. The energy position Et1 of the deep level was determined (calculated from the valence band edge at Et1= 0.89-0.9 eV). We demonstrated that SCLC was the main mechanism limiting the operating voltage and, consequently, a major factor in the performance and use of Cd(Mn)Te-based ionizing radiation detectors with ohmic contacts.