Abstract: In order to achieve reproducible vibration excitation of a quartz crystal even under the technical conditions which prevail when it is used for monitoring electroplating baths, a mounting for the quartz crystal 7 is proposed. The mounting for the quartz crystal 7 has two holding elements 3, 6, 14 detachably connected to one another as a form-fit, and at least two contact elements 5, 9 on the holding elements 3, 6, 14 brought into electrical contact with the contacting surfaces 32 of the quartz crystal 7. The quartz crystal 7 is fitted with the holding elements 3, 6, 14 and/or the contact elements 5, 9 at least one of the contact elements 9 being configured as a resilient body. The at least one resilient contact element 9 has an end face 34, 134 for electrically contacting the quartz crystal 7, the size of which face corresponds roughly to the size of the quartz crystal 7.