[en] Quantum theory of the relativistic string with fixed ends is constructed in the time-like gauge. The gauge conditions are introduced in the reparametrization-invariant action of the string. In the theory there are no tachyon states and constraints on the dimension of space-time. The constraints and gauge conditions are fulfild in quantum theory only as the matrix elements with respect to physical state vectors. The string generates the static interquark potential V(R)=√γ²R²+epsilon₀, where epsilon₀ is free parameter determined in the experiment