Improvements in mining by the application of electronics necessitates analy- sis of the objectives and problems. A detailed analysis has shown that increased tunel- ling performance is one of the most important objectives. In mining, the environmental conditions for machines, their handling and servicing are very hard. Therefore a health monitoring system for tunnelling machines in hazardous areas has been developed. This system measures operational parameters, such as-flow, pressure, temperature, etc., de- rives forecasts of possible failures from these values, and assists maintenance person- nel. Important data are transmitted to a surface computer via telephone cables. Health monitoring is based on the cognition that slow deterioration of characteristic parame- ters, e.g. fluid loss, are symptoms of wear. Sudden changes of machine parameters indi- cate sudden destruction. Computer technology is very advanced, but transducer technolo- gy has not,been able to keep pace. Filling the yawning gap in the mining industry is a challenge to technology and requires special techniques. Machine monitoring and automa- tion in underground mining is still in its infancy. A lqt of development and research work is still necessary. The risks are great-The expected benefit due to increased min- ing performance (up to 5 %) justifies the risks in development.