an angular - position measuring device includes a shaft rotatable relative to a body about an axis extending in a z - direction . a measuring standard having an end face is fastened on the shaft in rotatably fixed manner . the body includes a scanning device for scanning the measuring standard . both the roller bearing and a sealing unit are provided on the side of the measuring standard facing the end face relative to the z - direction , the sealing unit includes rings that are rotatable relative to each other and are separated from each other by a gap , the gap being filled at least partially with a fluid .