The prayer hall is a square room under a single dome 16.3 metres across. An octagonal zone, pierced by small windows, carries the round dome over the square walls.
The dome is covered in sheets of lead, and so is the tall cone of the minaret.
The minaret rises 47 metres. Its slender, many-sided shaft is built of pale cut stone. Carved stalactite corbels, called muqarnas, carry the single balcony, the şerefe, from which the call to prayer was once given.
Above it a short upper shaft ends in a tall cone covered in lead.
Before the door stands a portico of pointed arches on stone columns, each bay under its own small dome.
The building is set on the qibla, the direction of Mecca: the door faces north-west, and the mihrab, the prayer niche, is in the south-east wall opposite.
The walls are built of alternating courses of cut stone and brick, which gives them their banded look.
Rows of windows light the hall: rectangular ones low down, pointed arches above them and smaller openings near the top. With its portico, the building measures about 28 by 22 metres.
The mosque was once the centre of a larger endowment with a türbe, a fountain, a public kitchen (imaret) and a school (medrese).
Of these, the türbe, an eight-sided tomb under a dome east of the hall, and the ablution fountain survive. According to the Macedonian Wikipedia, the türbe holds the sarcophagus of Mustafa Pasha’s daughter, Umi.
In the yard in front of the portico stands the şadırvan, the fountain where worshippers wash before prayer. It is one of the two parts of the old complex still standing.
Here it is drawn as a stone basin under a small roof on columns; the details of the model are an estimate.