Is machinary cost fixed cost or variable cost?

The machine itself is neither. It's an asset.

Costs associated with the machine could be either. For instance, the depreciation is fixed. Electricity to run it can be variable.

You have to keep in mind that variable costs are those which change with production level. i.e. it would cost x dollars PER each unit produced. So if you only produce one, you only incur that cost once. If you produce 10,000, you have that cost for each of the 10,000.

Fixed costs are going to happen no matter what your production level. Since depreciation is usually based on a method not related to production level, that's fixed. It's set up when the machine is purchased and you depreciate x amount each year regardless of how much you produce. So it's a set amount for the year. Many administrative costs are fixed, such as the president's salary. The president is on a set salary that gets paid whether you produce 10,000 units or 15,000 units.