The Tenerife Microwave Spectrometer (TMS) is part of a renewed effort to study and characterize the CMB frequency distribution. The spectrometer is based on a pseudo-correlation architecture with two 10-20 GHz radiometer chains making use of both orthogonal linear polarizations, and will observe in this band with an angular and frequency resolutions of 3° and 1 MHz. The optical arrangement includes two corrugated feedhorns, one facing an internal calibrator to provide a cold reference signal, and the other pointing to the sky through the cryostat window by means of an offset-fed reflector. The optical system provides optimal cross-polarization properties (<=-30 dB) and symmetric beams, with minimum frequency dependence. The readout system is based on a SoC FPGA, providing fast data acquisition, high spectral resolution and stability. We present the current status of the TMS instrument, having described the scientific case of this instrument in the accompanying publication.