Machine’s spare parts are very important to support maintenance and repair ship’s machine. The purpose of this research is to find out the spare parts availability for ship’s machine and the level of smooth-running operation, and also to analyze the relationship between spare parts’ availability for machine and the level of smooth-running operation of MT. Gede of PT Pertamina (Persero) Jakarta in 2017. To solve the problem, the writer used field research method and library research for collecting data, and data analysis technique used Likert scale. Based on the result, this research shows that Simple Linear Regression Analysis obtains Ŷ = 8,068 + 0,837X which means every increase in spare parts’ availability for machine that is 1 unit of SKU (stock-keeping unit) will increase the level of smooth-running operation of MT. Gede about 0,837 point for PT Pertamina (Persero) Jakarta with 8,068 constant. A correlation coefficient obtained r XY = 0,740 which means the spare parts’ availability for machine has strong relationship between the level of smooth-running operation and PT Pertamina (Persero) Jakarta, because value of r = 0,740 means there is a positive and strong correlation between variable X (the spare parts’ availability for machine) and variable Y (the smooth-running operation of MT. Gede) that can be seen on interpretation of correlation table in Chapter I. The determinant coefficient is Kp = 54,7% which means relationship of contribution of the spare parts availability for machine is about 54,7% and the rest is about 45,3% for other factors outside the variable of this research, such as relationship of tools quality, skill of the ship’s crew, and other obstacle. The hypotesis testing obtained is tcount (5,816 > 1,701) so Ho is rejected and Ha is accepted. It means that there is a significant relation between variable X (the spare parts’ availability for machine) and variable Y (the smooth-running operation of MT. Gede) so the hypotesis stated in Chapter 1 is absolutely true.