A magnetic recording read head is provided capable of achieving high reproduction output, resolution, and SNR, even at a high linear density. There is also provided a magnetic recording and reproducing device capable of achieving sufficient error bit rate. The magnetic recording read head includes a differential read head and a write head. The differential read head has a multilayer structure formed by laminating a first magnetoresistive sensor having a first free layer, a differential gap layer, and a second magnetoresistive sensor having a second free layer. Outside the multilayer structure, a pair of electrodes and a pair of magnetic shields are provided respectively. A ratio (Gl/bl) of an inside distance (Gl) between the first and second free layers to a bit length (bl) is set to 0.6 or more and 1.6 or less.