We report on the design and performance test of a multiple laser Mueller matrix ellipsometer (MME). The MME is well conditioned due to the integration of the recently reported achromatic compensators based on biprisms, in combination with high-quality Glan-Thompson polarizers. The system currently operates between 300 and , without the need to change any optical components except for the detector. Four lasers are employed as light sources (405, 532, 633, and ) to test the performance in both reflection and transmission modes. Thus, the system is used to determine the Mueller matrices and associated optical constants of known optical systems: 1. optical rotatory power of D-glucose in solution, 2. reflection of a native oxide c-Si wafer, and 3. the properties of a liquid crystal spatial light modulator. The results show that the system matrices of the MME have condition numbers between the optimal and 2 during operation, resulting in small experimental errors. To the best of our knowledge, there is no other MME reported with such good conditioning over a comparably wide spectral range.