The topic of this diploma thesis is the planning of the expansion of the quarry Starkenbach. The appropriate operation is a mine of hard stone and is located in Swiss. Near Vaduz, in the Swiss canton St. Gallen, the mined material is processed to sand, chips, gravel and gobbles. The product is used as foundation gravel for railway rails, as addition in road pavements and in other unbound mixtures. The mine is performed by Mr. Peter Bitschnau. At the moment the company is planning a bordering expansion of 5ha. This thesis has a preparatory bachelor thesis (Zettl, 2015). A model of the deposit was created in this work. In this thesis geotechnical investigations are used for the planning of the mine operation in the quarry. The regional stability is examined with the rock classification methods of Bienawski, Hoek, Barton and Laubscher. The results of these studies are used for the two strength criteria from Mohr and Hoek which are used to calculate the strength parameters of the rock. The investigations concerning local stability are started with the recording of discontinuities sector by sector. The recovered data were put into the Schmidt net. After that, probable orientations of discontinuities can be used to orientate the mining front in a way that stability problems by rock slide can be minimized. On Basis of the regional and local stability studies a mining plan was done. The development of the mine in future years is shown step by step for the next 5, 10, 15, 20 and 30 years. As yearly mining mass an amount of 77.000 m³ were adopted.