Who made the calculator?

Answer 1

Many companies. The first "scientific" calculators were mechanical calculators that were hand cranked and were built in the early 1920s by companies like Marchant, Monroe, and Sumlock based on their earlier business calculator designs going back to the 1880s. The main difference was that the "scientific" calculators had more digits and came with booklets giving algorithms to calculate commonly used functions needed in science and engineering (e.g. trigonometry, logarithms, roots).
Electronic scientific calculators came much later (1960s to 1970s) and were also made by many companies like Hewlett Packard, Texas Instruments, Smith Corona Marchant, and Sinclair.

Answer 2

Blaise Pascal is often credited with invented the first calculator type machine around 1641